Reducing Display Monitor
Flicker

THIS DOCUMENT DOES NOT REPRESENT A POSITION OF SEATTLE COMMUNITY NETWORK. This
is personal opinion of the author, and SCN doesn't even take a position as to
its accuracy! The official SCN help page is linked above.

EXPLANATION

Monitor flicker particularly affects people in the autism spectrum including
people with Asperger's Syndrome. Monitor flicker can also provoke migraines.

Humans can perceive lights flickering up to 25 Hz. Even though not
perceptible, flicker at much higher frequencies affects people by
causing eyestrain. Many people find fluorescent lighting to cause eyestrain,
although fluorescent lights flicker at 120 Hz in North America
(100 Hz in countries with 50 Hz power). Continuous work behind a
monitor running at 60 Hz will be particularly stressful for someone with
Asperger's Syndrome. (So why does Bill Gates refer to his high end operating
system as "NT"?)

Flat panel displays are not significantly affected by this.

Screen flicker is most obvious when viewed from a distance, with fluorescent
lighting in the room.

Windows normally will identify the monitor as a "Standard SVGA
Monitor". The default drive speed for a "Standard SVGA Monitor"
is approximately 60 Hz. (Setting drive speed to "optimum" may
increase this slightly; and perhaps up to 75 Hz.). The "Standard
SVGA Monitor" default will normally occur even with factory "package
configuration" computers, since monitor selection is still a Windows
function.

Many "plug and play" monitors do provide information which is
recognized by Windows. Sometimes the type of monitor isn't indicated in the
settings, but the refresh rate options (e.g., 85 Hz) are given in the
"Adaptor" settings. So..

If you can select a refresh rate of at least 75 Hz, you almostly
certainly have a monitor defined by Windows. The
"refresh rate" is found in display properties -->
<settings> --> <advanced> --> <adapter> -->
<refresh rate>

The monitor selection is normally just an .inf file which
identifies the refresh rates of one or more monitors. It is not a true
software device driver. The device driver is associated with the video card.
The video card device driver software uses the monitor's .inf
information to offer you the different drive speeds.

So the purpose of this page is to attempt to upgrade the settings so as to run
the monitor at higher speed.

NOTE: This only works for SVGA monitors. All modern monitors are
SVGA. (The old VGA monitors from the early '90s typically only go up to 60Hz.)

WHAT TO DO IF YOU MESS-UP

Restart the computer and run in "Safe Mode" (W98) or "VGA
Mode" (NT). Then reduce the monitor frequency and try again. If you pay
attention to the screen prompts, this shouldn't be a problem, because Windows
will request a confirmation of the change. But I've done it wrong a couple of
times!

If your monitor ever blanks out when you try to adjust the frequencies, just
don't touch anything and wait 15 seconds patiently. The screen should
return to its previous state again. This means the setting you selected is not
compatible with the monitor and you shouldn't use it.

"INSTALL" THE MONITOR

CHECK WHAT YOU HAVE

Look at display properties to see if the monitor is already identified:

RIGHT click on the desktop background ("white space").
Select <properties>.

<settings> - On Windows98 and later the display type and video card
should appear on that window. If not continue..

click <advanced>.

Look under <monitor> and <adaptor> to see that the monitor is
correctly identified. The <adaptor> window should have a selection box
which allows selection of different monitor speeds. (A custom installation may
have a different monitor defined; this may be okay. Some also say
"Standard Plug-and-Play" even if they define a proper set of refresh
rates.)

If the monitor is already "installed", then select a high refresh
rate and enjoy!

IF YOU HAVE A COMPUTER PERSON WHO CAN DO IT

Okay, the display says "Standard VGA". You work for a business or
other entity which has an on-site MIS department. Just ask that they
"load the monitor driver information files" for the monitor, and that
you want that so that you can "set the monitor to its highest refresh
rate."

GET THE DRIVER

Look for the model designation of the monitor. If you have a newer monitor
or are running Windows 95, go onto the net and find "[brandname] Display
Driver". Download it.

Open the downloaded file in a logical place such as
\windows\system\drivers\monitor\sony. (Make a directory for
this.) If the file is brandname.inf, just place
that file in the selected directory.

While you're at it, go to the "my computer" or
"explorer" and change the properties of the
\windows\inf\ folder so that it is NOT hidden. It's
difficult to browse for an .inf file in that directory if the
directory is hidden!

INSTALL THE DRIVER

RIGHT click on the desktop background ("white space").
Select <properties>.

<settings> - On Windows98 and later the display type and video card
should appear on that window. If not continue..

Click <advanced>.

Click on <monitor>.

Click <change>.

Proceed to driver selection.

Select "have disk".

Browse until you get to the location of the .inf file that
you've downloaded. Usually the file name will appear in the box when you've
gotten to the right place.

Select that file.

Identify the monitor if there is a choice.

When the file is installed, go back to the <adaptor> setting
above and change the drive rate.

When the file is installed, go back to the <adaptor> setting above and change the drive rate.

Enjoy!

PROBLEMS

Image Bad or No Image

Go to a slower rate and try again. If necessary start in "Safe
Mode" or "VGA Mode".

If your monitor ever blanks out when you try to adjust the frequencies, just
don't touch anything and wait 15 seconds patiently. The screen should
return to its previous state again. This means the setting you selected is not
compatible with the monitor and you shouldn't use it.

Program Crashes related to Graphics Driver

Sometimes this can be caused
by full "hardware acceleration". This is in the monitor
"performance settings":

RIGHT click on the desktop background ("white space").
Select <properties>.

<settings>

click <advanced>.

Look under <performance> and select "none" for
"hardware acceleration.". If that fixes the problem, try
intermediate "hardware acceleration" settings to see if they work.
This is a known bug with WordPerfect for Windows.

A program immediately crashes with the faster settings.

Try the program
at the slower video speed, and then go back to the higher speed. Sort of black
magic but it does work!

Other "fatal error" program crashes related to video.

Write down the name of the module and go out on the net and see if someone
somewhere addressed the issue. If not in your program, it may appear in
something else.

ALTERNATE APPROACH - GENERIC MONITOR SETTINGS

Here is another approach, from Eric Chen Yixiong, explaining how to obtain
higher refresh rates on a "generic" monitor.

I noticed some of you here may want to minimise screen flicker. I can actually
see the monitor flicker at 60Hz and even a little at 72Hz. If you want to
reduce eyestrain or stress (I read that flickers can affect AC behaviour), then
you can either get an LCD screen or change your monitor refresh rate.

Warning: The method may damage your monitor in some special cases (though it
never happened to me), try it at YOUR OWN RISK and with computer competent
people to help you!

Before doing it, please ensure your monitor is not VGA but SVGA or better. SVGA
monitors usually cannot support refresh rates higher than 60Hz. Generally,
those newer monitors from 1995 onwards are all SVGA.

If you use Win95 or Win98, go to Start Menu, select Control Panel and then
Display. In Display, go to Settings and click Advanced. Select the section
"Adapter". You should see an option called "Refresh Rate". Click on it.

If you see a list of frequencies, skip to Step 4. If you don't see any numbers
(but just "Default" and "Optimum"), go to section "Monitor". Make sure your
monitor or display card doesn't have special drivers (like some Voodoo 3 cards)
that you may accidently interfere with if you change your settings.

Click on "change", click "Next", then select "Display a list of all drivers..."
and either select the "Super VGA 1028X768 @ 75Hz" monitor (if you had
Win98, which saves you the trouble of the step 4) or the Acer 78i (which
usually works). Click "Next" until you get to "Finish". After you changed your
monitor, you should see that the Refresh Rate option shows you the list of
frequencies.

Go to the "Adapter" section with the "Refresh Rate" option. To start testing,
you should start from 72Hz and click Apply. If your monitor can work properly
then you can try 75Hz. Generally the larger the number the better but some
monitors may get damaged more easily if you set the refresh rate too high, so
try anything above 85Hz and at your own risk.

If your monitor ever blanks out when you tried to adjust the frequencies, just
don't touch anything and wait 15 seconds patiently. The screen should
return to its previous state again. This means the setting you selected is not
compatible with the monitor and you shouldn't use it.

As for other systems other than Win2k, sorry, I do not use them and thus I
cannot provide advise.

WHY DOES THIS AFFECT PEOPLE WITH ASPERGER'S SYNDROME?

I don't know.

Normally the monitor settings are just left alone. People with Asperger's
Syndrome tend to be particularly sensitive to video flicker, and so flicker is
an issue for people with Asperger's Syndrome. That's why I posted this.

Asperger's Syndrome (AS) is the same as or similar to high functioning autism
(HFA) and results in a person being object-focused rather than person-focused.
An "Aspie" will not easily follow body language in conversation.
Occasionally AS people have particular intellectual "special
interests". Famous people who have been described as having AS
characteristics include Albert Einstein, Vincent VanGogh,
Leonardo daVinci and Temple Grandin. Bill Gates and
Al Gore have also been described in this manner but have not
self-identified as Aspies.